Switch box test

[Biskitboy]

Rookie here ,
i have a 88 115 mariner inline 6. Getting no spark on 2,4,6. Good spark on 1,3,5. Swapped leads and still no spark. So is it likely switch boxes? I have removed both of them is there any test that can be done on bench? I unhooked bias wire and swapped leads and still only spark on 1,3 no spark on2,4,6,5. All test done with timing light. Is it imperative that I replace both boxes?
thanks a lot ( will probably need a lot of help)

[flabum1017]

http://www.cdielectronics.com/troubleshootingguide/

[Merc 2.5]

So u swapped the boxes/leads around and it was same cylinders? It is recommend that both get swapped, I did swap 1 not long ago and next trip the other went out , swap both if its ur prob,

[Motv18]

Never had good from doing just one.

Unless you you have to run that day and it’s all there is.

When one goes goes the other is not far from dead.

[Dave Strong]

Replace both always.

Dave

[Forkin' Crazy]

Never had good from doing just one.

Unless you you have to run that day and it’s all there is.

When one goes goes the other is not far from dead.

Yep!!! It seems like when one goes out, it takes out the other. I vote for replacing them both too.

[Dave S]

Switch boxes are like light bulbs....they go out with a flash......Stator is next, 30 year motor.

[smako78]

I believe it's a trigger coil or trigger coil lead wire up by the flywheel! Think about the swap test? I have run bad diode circuit ecm,s ( cuts out 1 cyl) for over 200 gal's gas / 3 year's just by disconting the 12v ac charge wire to the DC reg. Comments good or bad on what I don't matter I know what worked for me! Hope this helps Steve.